San Antonio Mountain is an isolated volcanic peak in northern New Mexico and the highest summit in the Taos Plateau volcanic field, making it a prominent landmark visible across the lower San Luis Valley and beyond. Rising in Rio Arriba County near Rio Grande del Norte National Monument within Carson National Forest, it is a dacite dome formed by eruptions about 3.36 to 2.9 million years ago. Known to Tewa-speaking peoples as Kay Pʼin, or bear mountain, and regarded in Tewa cosmology as the mountain of the north, it is also ecologically important for its forests and wildlife, including one of New Mexico’s largest elk populations.